NEEDHAM, Mass. — Music soothes the savage breast, or so the adage says. This premise underlies the reliance upon music as a safety tool on school buses.

But not all music is soothing, and unruly children on a school bus are not easily tamed. More importantly, not all radio music is age-appropriate, be it for the well-mannered or disruptive child. Talk radio and Top 40 radio alike often are laced with explicit content unsuitable for children. Still, many bus drivers crank up the radio hoping it will keep the students quiet. Seated. And entertained.

Entertainment, specifically age-appropriate entertainment that strives to make the bus ride more enjoyable for the driver and the students, is being offered by Bus Radio, a Needham, Mass.-based start-up firm that is promoting free digital radio programming specifically for school buses.

“When Bus Radio was presented to me, I was excited to know there will be some positive possibilities to help bus drivers, transportation staff, parents and school administrators,”said Susie Fields, transportation director for Franklin Township (Ind.) Schools. “The daily format will comprise good, age-appropriate music and safety announcements.”She said the commercials will also be age-appropriate and that any food endorsements will follow wellness program guidelines.

If it sounds too good to be true, it just may be. While proponents tout it as a win-win, Bus Radio is swamped with controversy and has a fair share of opponents — many of whom are heavy hitters with powerful political clout.

For example, a consumer watchdog group called Commercial Alert drafted a petition against Bus Radio endorsed by 64 children’s advocates groups and 40 organizations, including the American Family Association, Consumer’s Union and the National PTA. Campaign for Commercial-Free Childhood has a similar petition circulating.

In addition, Sen. Byron Dorgan of South Dakota introduced an amendment to the Senate Commerce Committee last June requesting an FCC “Bus Radio”study. The committee unanimously voice-vote approved the amendment, which is attached to a pending bill that has moved on to the House.

Even some school districts are hopping off the Bus Radio bandwagon. A district in Mansfield, Mass., pulled the plug on plans to install the service after being hit with an onslaught of angry parental e-mails, letters and concerns.

The controversy?

Eight minutes per hour are dedicated to plugs — aimed specifically at the teen and tween markets. Another two minutes are contest promotions. Opponents contend Bus Radio crosses the line, giving aggressive advertisers access to impressionable young minds that do not yet possess the critical thinking faculties required to determine truth versus well-crafted hype.

But Bus Radio proponents argue that age-appropriate commercials are better than ones geared for adults. As for the music, Bus Radio uses three-tier content screening that includes a review board comprising educators, child psychologists and parents. Programming also includes safety tips for children, such as how to exit and enter a bus.

As for the watchdog groups’ concerns, Bus Radio founder Steve Shulman said that both sides are on the same page. “We are both trying to protect children from inappropriate content,”Shulman said. “Once people are educated about our product and goals, they realize we are trying to accomplish the same thing as the watchdog groups.”

So while a dialogue seems to have been established, the hot button question remains — is Bus Radio an enjoyable, educational, child-friendly radio format alternative, or a slick marketing gimmick targeted at a contained and captive audience — children riding to and from school on a bus?